Stressed? The unexpected reasons why

We're told not to sweat the small stuff, but sometimes it's the little things that have the biggest impact on our mood: the never-ending phone calls with your insurance company, the rude cashier at the grocery store, the 20 minutes you lose looking for a parking space. "We let these things bother us because they trigger unconscious fears," says Yeager—fears of being seen as irresponsible, of being bullied or embarrassed, or of being late all the time, for example. "Sometimes you need to take a step back and realize that you're doing the best you can given the circumstances."

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Stress is contagious, according to a 2014 German study: In a series of experiments, most participants who simply observed others completing a stressful task experienced an increase themselves in production of the stress hormone cortisol—a phenomenon known as empathic stress. You can also experience stress when someone you know is affected by a traumatic event, like a car crash or a chronic illness. "You start to worry, 'Oh my gosh, could that happen to me?'," says Yeager. "We tend not to think about these things until they hit close to home."

It may seem like Facebook is the only way you keep up with the friends you don't see regularly—which, during particularly busy times, can be just about all of them. The social network also has a downside, according to a 2015 study from the Pew Research Center: It can make you aware of stressful situations in your friends' lives, which in turn can add more stress to your life. The Pew report didn't find that social media users, overall, had higher levels of stress, but previous studies have suggested that frequent social-media use can be associated with negative body image and prolonged breakup pain.

A distraction can be a good thing then when it takes your mind off of a stressful situation or difficult decision, like when you take a break from work to meet a friend for lunch. But it works the other way, as well: When you're so busy thinking about something else that you can't enjoy what's going on around you, that kind of distraction can be a recipe for stress. Practicing mindfulness gives you brain the refresh it needs, says Richard Lenox, director of the Student Counseling Center at Texas Tech University. Paying full attention to your surroundings when you're walking and driving can help, he adds. "Stress and anxiety tend to melt away when our mind is focused on the present."

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Traumatic events that happened when you were a kid can continue to affect your stress levels and overall health into adulthood. A 2014 University of Wisconsin-Madison study found that these childhood experiences may actually change parts of the brain responsible for processing stress and emotion. The way you were raised can also have a lasting impact on your everyday angst, suggests a 2014 Johns Hopkins University study. Researchers found that children of parents with social anxiety disorders are more likely to develop "trickle-down anxiety"—not simply because of their genes, but because of their parents' behaviors toward them such as a lack of warmth and emotion, or high levels of criticism and doubt.

You probably know to take it easy on the coffee when you're already feeling on edge. "Caffeine is always going to make stress worse," says Yeager. But you may not think as much about drinking several cups of tea at once, or chowing down on a bar of dark chocolate—both of which can contain nearly as much caffeine as a cup of joe. "Chocolate is a huge caffeine source," says Yeager. "I know people who don't drink coffee but they'll eat six little candy bars in a two-hour period because they want the same kind of jolt." Too much caffeine, in any form, can cause problems with sleep, digestion, and irritability.

When things don't go the way you've planned, do you tend to get upset and act defensively, or do you roll with the punches and set off on a new plan? If it's the former, you could be contributing to a mindset of pessimism and victimization that will slowly wear you down, even when things may not be as bad as they seem. "Your level of serenity is inversely proportionate to your expectations," says Yeager. That doesn't mean you shouldn't set ambitious goals for yourself or settle for less than what you want, of course, but being realistic about what's truly possible is important, as well.

If you tend to deal with stressful situations by working long hours, skipping your workouts, and bingeing on junk food, we've got some bad news: You're only making it worse. "We know that physical activity and healthy foods will help your body better deal with stress, and yet we often avoid them when we need them the most," says Yeager. "People really need to think about this downward spiral we get into and work harder to counteract it."

Think you're being super efficient by tackling four tasks at once? Chances are you're not —and it's only decreasing your productivity while increasing your stress. A 2012 University of Irvine study, for example, found that people who responded to emails all day long while also trying to get their work done experienced more heart-rate variability (an indicator of mental stress) than those who waited to respond to all of their emails at one time. Focusing on one task at a time can ensure that you're doing that job to the best of your abilities and getting the most out of it, so you won't have to worry about or go back and fix it later, says Schieman. And don't worry: You'll have enough time to do it all. In fact, you may discover you have more time than you thought.

Watching a tight game of college hoops can stress you out—even if your alma mater wins. "The body doesn't distinguish between 'bad' stress from life or work and 'good' stress caused by game-day excitement," says Jody Gilchrist, a nurse practitioner at the University of Alabama at Birmingham's Heart and Vascular Clinic. Watching sports can even trigger the body's sympathetic nervous system, releasing adrenaline and reducing blood flow to the heart. Those temporary consequences aren't usually anything to be concerned about, but over time, chronic stress can lead to high blood pressure and increased disease risk. And, of course, it doesn't help if you're adding alcohol and binge-eating to a situation that's already stressful on your body. You may not be able to control the outcome of the game, says Gilchrist, but you can limit its effects on your own body.

Whether you're using it for work or play, technology may play a large role in your mental health, says Yeager. Using computers or e-readers too close to bedtime could lead to sleep problems, he says, and spending too much time virtually socializing can make real-life interactions seem extra stressful. (Plus, texting doesn't trigger the same feel-good hormones as face-to-face talk does.) Then there's the dreaded "work creep," says Schieman, when smartphones allow employees to be tethered to their jobs, even during off-hours. "People say they're only going to check email for an hour while they're on vacation, but the problem with email is that they're filled with responsibilities, new tasks, and dilemmas that are going to be hard to compartmentalize and put out of your head once that hour is up."

While it may not be as stressful as having a chronic illness or getting bad news at the doctor's office, even people in the best shape of their lives worry about their bodies, their diets, and their fitness levels. In fact, people who take healthy living to an extreme may experience some rather unhealthy side effects. People who follow low-carb diets, for example, are more likely to report being sad or stressed out, while those on any kind of restrictive meal plan may feel more tired than usual. And it's not unheard of for someone to become obsessed with healthy eating (known as orthorexia) or working out (gymorexia). Like any form of perfectionism, these problems can be stressful at best, and extremely dangerous at worst.

Does folding laundry help you feel calm, or does it make your blood boil? If you're in a living situation where you feel you're responsible for an unfair share of work, even chores you once enjoyed may start to feel like torture. "Dividing up housework and parenting responsibilities can be tricky, especially if both partners work outside the home," says Schieman. "And whether you define that division of labor as equal or unequal can really change your attitude toward it."

Stress can be defined as any perceived or actual threat, says Yeager, so any type of doubt that's looming over you can contribute to your anxiety levels on a daily basis. "When you know something could change at any minute, you always have your guard up and it's hard to just relax and enjoy anything." Financial uncertainty may be the most obvious stressor—not being sure if you'll keep your job during a round of layoffs, or not knowing how you'll pay your credit card bill. Insecurities in other areas of life, like your relationship or your housing status, can eat away at you too.

No matter how much you love your furry friends, there's no question that they add extra responsibility to your already full plate. Even healthy animals need to be fed, exercised, cleaned up after, and given plenty of attention on a regular basis—and unhealthy ones can be a whole other story. "Pets can be the most positive source of unconditional love, but at the same time they require an extreme amount of energy," says Yeager. People also tend to underestimate the stress they'll experience when they lose a pet. "I've had people in my office tell me they cried more when their dog died than when their parent died. It's a very emotional connection."

Having a college degree boosts your odds of landing a well-paying job, so although you're less likely to suffer from money-related anxiety, your education can bring on other types of stress, according to a 2014 study by Schieman and his University of Toronto colleagues. His research found that highly educated people were more likely to be stressed out thanks to job pressures, being overworked, and conflicts between work and family. "Higher levels of authority come with a lot more interpersonal baggage, such as supervising people or deciding whether they get promotions," says Schieman. "With that type of responsibility, you start to take things like incompetency and people not doing their jobs more personally, and it bothers you more."